Tuning the RabbitMQ Transport

RabbitMQ transport allows you to send or receive AMQP messages by calling an AMQP broker (RabbitMQ) directly. In order to improve the performance of the RabbitMQ transport you can do following.

Set queue and exchange declaration parameters to false

Setting rabbitmq.queue.autodeclare and rabbitmq.exchange.autodeclare parameters in the publish url to false can improve the RabbitMQ transport performance.

When these parameters are set to false RabbitMQ does not try to create queues or exchanges if queues or exchanges are not present. However, you should set these parameters if and only if queues and exchanges are declared prior on the broker.

Increase the connection pool size

You can increase the connection pool size to improve the performance of the RabbitMQ sender and listener. The default connection pool size is 20. To change this, specify a required value for the following parameter in the RabbitMQ transport sender and listener configurations in the <EI_HOME>/conf/axis2/axis2.xml file.

<parameter name="rabbitmq.connection.pool.size" locked="false">25</parameter>

<transportReceiver name="rabbitmq" class="org.apache.axis2.transport.rabbitmq.RabbitMQListener">
   <parameter name="AMQPConnectionFactory" locked="false">
      <parameter name="rabbitmq.server.host.name" locked="false">localhost</parameter>
      <parameter name="rabbitmq.server.port" locked="false">5672</parameter>
      <parameter name="rabbitmq.server.user.name" locked="false"></parameter>
      <parameter name="rabbitmq.server.password" locked="false"></parameter>
      <parameter name="rabbitmq.connection.retry.interval" locked="false">10000</parameter>
      <parameter name="rabbitmq.connection.retry.count" locked="false">5</parameter>
      <parameter name="rabbitmq.connection.pool.size" locked="false">25</parameter>
    </parameter>
</transportReceiver>

<transportSender name="rabbitmq" class="org.apache.axis2.transport.rabbitmq.RabbitMQSender">
   <parameter name="RabbitMQConnectionFactory" locked="false">
       <parameter name="rabbitmq.server.host.name" locked="false">localhost</parameter>
       <parameter name="rabbitmq.server.port" locked="false">5672</parameter>
       <parameter name="rabbitmq.server.user.name" locked="false"></parameter>
       <parameter name="rabbitmq.server.password" locked="false"></parameter>
       <parameter name="rabbitmq.connection.retry.interval" locked="false">10000</parameter>
       <parameter name="rabbitmq.connection.retry.count" locked="false">5</parameter>
       <parameter name="rabbitmq.connection.pool.size" locked="false">10</parameter>
   </parameter>
</transportSender>

Increasing the member count

If you set the following parameter to false in the <EI_HOME>/conf/axis2/axis2.xml file, it sets the configuration to handle the acknowledgement in the application level: <parameter name="rabbitmq.queue.auto.ack">false</parameter> 

Thus, it sends back the acknowledgement once it sends the request to the back-end. (i.e., It does not wait for the response). However, in a message store/processor implementation, it waits for the response to send the acknowledgment back to provide guaranteed message delivery. Therefore, there might be a delay in processing messages using message processors than using a message producer/consumer implementation.

However, you can increase performance of message processors either by increasing the member count or by having multiple message processors. If you increase the member count, it will create multiple child processors of the message processor.

Reuse the connection factory in the publisher

In the publisher url, set the connection factory name instead of the connection parameters as specified below in the rabbitmq.connection.factory parameter . This reuses the connection factories and thereby improves performance.

<address uri="rabbitmq://?rabbitmq.connection.factory=RabbitMQConnectionFactory&amp;rabbitmq.queue.name=queue1&amp;rabbitmq.queue.routing.key=queue1&amp;rabbitmq.replyto.name=replyqueue&amp;rabbitmq.exchange.name=ex1&amp;rabbitmq.queue.autodeclare=false&amp;rabbitmq.exchange.autodeclare=false&amp;rabbitmq.replyto.name=response_queue"/>